May 26, 2007: Greenhouse Extinctions - Peter Ward

Art Bell welcomes back Peter Ward, professor of biology and earth sciences at the University of Washington and NASA Astrobiology Institute investigator, to discuss his book Under a Green Sky and the science of mass extinctions. Ward explains that while the dinosaur extinction 65 million years ago was caused by an asteroid impact, the other 15 mass extinctions over 500 million years show no such evidence. Ward presents his theory that most mass extinctions were driven by greenhouse gas-induced… Full show notes & guests: https://artbellarchive.org/episode/may-26-2007-greenhouse-extinctions-peter-ward